3.1 Periodicity Flashcards
Chromium and copper exception
- ₂₄Chromium: acutal: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵ or [Ar] 3d54s1, expected [Ar] 4s2 3d4
₂₉Copper: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰ or [Ar] 3d104s1, expeted [Ar] 4s2 3d9
Because having one electron in each of the five d orbitals is more stable than having 4 filled and 1 empty/partially empty
a)state the group of alkali metal
b)state group of alkaline metal
c)state group of s,p,d,f
4)state the group of noble gas
states actinides and actinides
group
columns and number of valence electrons
Lanthanide
F block and part of 6th peroid
period
rows and shows number of occupied energy level or the number of outermost occupied level
Actinides
F block and part of 7th peroid
Atomic radius
The atomic radius is ½ the distance between two adjacent identical atoms in a covalent bond
Ionic radius
Distance between the nucleus and the outermost electrons
electron affinity
The energy change to form a mole of gaseous anions
- 𝑋(𝑔) + 𝑒 − → 𝑋(𝑔)
- 𝑋-1(𝑔) + 𝑒- − → 𝑋-2(𝑔)
- 𝑋-2(𝑔) + 𝑒- − → 𝑋-3(𝑔)
metalloids
An element that possesses some of the properties of a metal and some of a non-metal. While metal oxides tend to be basic and non-metal oxides tend to be acidic, metalloid oxides such as aluminum oxide can be amphoteric.
Define Periodic table
Periodicity refers to repeating trends or patterns of physical and chemical properties in elemen
State three properties that are characteristic of transitional elements
- variable oxidation state
- form complex ions with ligands
- form coloured compounds
- may act as catalyst (as a element or compound)
- Paramagnetic, diamagnetic…
Describe the trend atomic radii across the period
- number of protons increases (nuclear energy)
- number of electron shell/sheilding effect is kept the same
- effective nuclear energy increases and increased electrostatic attraction and distance between postively charged nuclues and valence electrons decreases
- smaller atomic radii
Decribe the atomic radii down the group
- increased energy level/shielding
- decreased electrostatic attraction and distance between positively chaged nucleus and valence electrons
- increased atomic radii
Describe the ionic radii down the group
No pattern due to varuable oxidation state of transitional metal
Why is Mg2+ smaller than Na+
- they are isoelectronic (same number of electron)
- Mg2+ has smalller nuclear charge (#protons)
Why is Cl- bigger than Cl?
- Anions are bigger than parent atom
- addiction of electron causing increased e-e reputsion causing the electrons to move further apart
- increased radii
Why is Mg2+ smalller than Mg?
- Cations are bigger than parent atom
- group 14~17: cations
- losses an outer shell
- decreased radii
Describe the ionic radius across period three
- Na+, Mg2+, Al3+, Si4+ decrease in ionic radius due to increased effective nuclear charge
- Si4-, big increase in ionic radius due to added energy level and more electrons than protons , decreased electroststic attraction
*Si4-, P3-, S2-, Cl- , decrease ionic radius due to increased effective nuclear charge
Explain ionization trend of Ca and Ti
Ca: [Ar] 4s²→ big jump after removing second e due to transition form fourth to third energy level
Ti: [Ar] 3d² 4s² → I.E increases gradually (4s and 3d similar) and does not jump till 5th electron, which explain varible oxidation state of Ti being 2+, 3+, 4+ but not +5
State the 2 exceptions to the ionization energy trend across the period
- Drop→ higher in energy level, further away from the nucleus
- Rise→ increased number of protons, effective nuclear charge
- Be~B→ The outer electron in B is in a 2P sublevel and therefore has higher energy and further away from the nucleus than the outer electron in Be which is in 2S usblevel. Therefore the 2P sublevel requires less enrgy to remove than than from 2S
- N~O→ three 2P electrons in nitrogens are unpaired. 4 electrons in 2P with one doubly filled in Oxygen experiences e-e repulsion therefore eaiser to remove
Explain the trend of succesive ionization energy of Na
- 1s2 2s2 2p6 3s1
- 3s1→ higher in energy level, further away from the nucleus → easiest to remove
- 3s1~2p6 → one energy level lost/lower in energy level→ less sheilding by inner electrons and closer to the nucleus
- 2s1~2p6 → number of protons stays same , more attraction between remaining electrons → higher effective nuclear chage → less e-e repulsion
First ionization energy
The minimum amount of energy needed to remove one moles of electrons from one moles of an element in the gaseous state
Always endothermic (energy absorbed) 𝑋(𝑔) → 𝑋(𝑔)+ + 𝑒−
- the metal have low I.E. and non metal have high I.E
trend for succesive ionization energy at same energy level of an atom
There is an increase in successive ionization energies. more electrons are removed the remaining electrons
experience an increasing effective nuclear charge and are held closer to the nucleus and hence more tightly
trend for large jumps in succesive ionization of an atom
a change to a new inner shell, closer to the nucleus/lower in energy level/with the electrons held more strongly
State reason to variables oxidation state of Al and Cr
*aluminium +3 +1and +2, electrons removed frm [Ne] 3s² 3p1 to make bondings with more stable atom
* Cr +1, +2, +3, +4, +5, +6, electron removed from [Ar]4s13d
Trend for electron affinity
- Group 17→ highest electron affinity → big incomplete energy level with highest effective nuclear charge
- Group 1 → lowest electron affinity → effetive nuclear charge of 1+
- metals have low affinity and non metal have high affinity
- Electronegativity
- Explain the polarity of S-O bond
- abillity of itos atom to attract electrons in covalent bond
- oxygen hav ehigher electron density/negative partial dipole
- Sulfur have low electron density/positive paritial dipole
Describe the melting point across period 3
- Na,Mg,Al (group1~13) increasing ionization energy→ increased valence E → increased delocalise to form more positively charged cations and a bigger sea of delocalised electrons.
- Si (group 14) increasing ionization energy → giant coavlent strucure → no mobile e
- S8, P4, Cl2 (group 15~17) decrease in melting poiny→ molecular mass and electron cloud size is in the order S8 > P4 > Cl2 → bigger electron cloud increased instaneous dipole-dipole force → increased melting point
What are physical properties and chemical properties onf alkali metal
physcial properties
- Melting points decrease as atoms become larger and therefore metallic bonds becomes weaker
- Reactivity increases down the group as the valence electron is easier to lose, due to shielding (cation)
- metals have low ionization energy (oxidized/lose electrons easily) and form ionic compmound with non-metal
- stored in oil to prevent oxide reacting with alkaline metals
Chemical properties
- conductor of heat and electricity
- malleable
- ductile (can be drawn into wires)
- Luster (shiny)
What are physical properties and chemical properties of halogens
physial properties
* they are colored
* gradual change from gases (F2, Cl2) to liquid (Br2) and soilids (I2 and At2)
* -insulator of heat and electricity
* brittle
* reduced (gain electrons)
Chemical properties
* They are very reactive non metal
* melting points increase as Van der Waal forces becomes greater with more electrons
* Reactivity decreases down group as with each consecutive element the outer shell gets further from the nucleus. So the attraction between the nucleus and electrons gets weaker, so an electron is less easily gained
* form ionic ocmpound with metals and covalent compoudns with other non-metals
What color is formed when displacement reaction happens with idodie halide
Brown
what color is formed when displacement reaction happens with bromine halide
orange
Describe the acidic property of period three
**Giant ionix structure are basic metal giant ionic with high conductivity at molten state **
Na2O (s) and MgO(s) has oxidation state of 1+,2+
* AlO3(s) has oxidtion state of 3+
** giant covalent structure is cidic non-metal and have low conductivity**
* (SiO2)n(s) has oxidation state of 4+
**molecular covalent are metal acidic oxide with no conductivity **
* P2O3(s) P2O5(s) both at solid state with oxidation state of +5 and -3
* So2(l), So3(g) have oxidation state of +6 and +4
* Cl2O(l), Cl3O7(g) have oxidation state of +7 and +1
Write equation
a. sodium oxide reacts with water
b. magnesium oxide reacts with water
Basic oxide + water= alkalines soluition with hydroxide ions
Write equation
a. oxgen ion and hydrogen ion
b. lithium oxide with hydrochloric acid
c. magenesium oxide with hydrochloric acid
basic oxide + acid= salt + water
write equation
a. water react with carbon dioxide (instead of insoluble sillicon)
b. water react with sulfure oxide
c. water reacts with dichlorine hexaoxide and dichlorine oxide
d. water reacts with phosphorus pentooxide and phosphorus trioxide
write equation
b. water react with sulfure oxide
write equation
c. water reacts with dichlorine hexaoxide and dichlorine oxide
write equation
d. water reacts with phosphorus pentooxide and phosphorus trioxide
- in acid
Write an equation
a. aluminum oxide reacts with HCL (base)
b. aluminium oxide reacts with sulfuric acid
alumnium oxide reacts with sodium hydroxide
Aluminium oxide does not affect the pH when it is added to water as it is essentially insoluble. It has amphoteric properties, however, as it shows both acid and base behaviour.
Carbon dioxide leads to ocean acidicity. Write an equation of water reacting with water
Sulfur oxide is used in fossil fuels and produces acid rain. Write an equation showing the formation of the acid rain:
a. sulfur and oxygen
b. product of “a” with water
c.product of “a” with oxygen
d. product of “c” with water
Nitrogen oxide is used for engine combustion and causes acid rain. Write an equation showing the formation of the acid rain:
a. nitrogen with oxygen
b. product “a” with oxygen
c. product from “b” with water
d. reactant from “c” with oxgen
a. What is an transitional metal with only one oxidations state
b. what is an transitonal metal with most oxidation state?
Define complex ion
charged particle in wich on or more ligands form coordinate bond to central postiive metal ion using one or morne of its long pairs of electrons
*transitional metal have high charge density attracting water molecules in a solution
Draw an simple diagram showing why the complex ion of transtion element are colored
Decribe the catalytic behaviour of transitional metal
- The 3d and 4s attracts electrons in other molecules. collisins lowers the strength of the coalvent bond (make & bond), lowering the activation and making the reaction faster.
Define
a. diamagemetic
b. paramagnetic
fully paired electrons cancles out the spinning so have no net magnetic force (no place to spin). Paramagnetism increases with the number of unpaired electrons, spinning makes larger magnetic field.
- Diamagnetic: No unpaired electrons. Weakly repelled in an external magnetic field
- Paramagnetism: One or more unpaired d-orbital electrons. Attracted by an external field (transtiional metal: they contain paried electron but unparied electrons are stronger than diamagentic effect).
Which elements are ferromagnetic?
- cobalt and nickel
- Largest magentic effect.
- large numbers of unpaired electrons line up with parraell spins called domain becoming more ordered. It aligns with the external field.
- indivisual magnetic moment add up, and large magenetic peroperty remain with no external sources
What are factors that effects the transitonal metal
- nuclear charge of the metal
- oxidation state of the metal
- shape of the complex
- nature of the ligand
Spectrochemical series
iron acts as catalyst to provide surface for the Harber process
1) write an formation equation of ammonia
2) Explain how transitional metals act as heterogenous catalyst
3) What is another examples of heterogenous catalyst
- N2(g) + 3H2 (g) → 2NH3 (g)
- Heterogenous: a different state from the reactant. It uses its 3d and 4s electrons to make weake bonds with the reacting molecules. It provide a surface for the reactant molecules to come together with the correct orientation
In the Contact Process for the conversion of sulfur dioxide into sulfur trioxide, vanadium(V) oxide acts as a heterogeneous catalyst. Write two equations to show how the catalyst is involved in this reaction.
Explainwhy transtional metals are effective homogeneous catalyst
- the same state of matter as the reactants. Its variable oxidation states allows them to be effective in redox reaction. They serve as biological importance (enzyme-catalysed reaction)
